Problem in finding the General Solution of a Trigonometric Equation v3

AI Thread Summary
The discussion revolves around finding the general solution for the trigonometric equation 3sin²(θ) + 7cos²(θ) = 6. The given answer is nπ ± π/6, but there is confusion regarding its correctness. Participants clarify that there is a π radian difference between certain angles, which leads to the conclusion that the solution can be expressed as ±π/6 + nπ, where n is any integer. This formulation encompasses all possible scenarios for the equation. The conversation emphasizes understanding the relationship between the angles rather than simply matching answers.
Wrichik Basu
Science Advisor
Insights Author
Gold Member
Messages
2,180
Reaction score
2,717

Homework Statement

:[/B]

Find the general solution of the Trigonometric equation: $$3\sin ^2 {\theta} + 7\cos ^2 {\theta} =6$$

Given andwer: ##n\pi \pm \frac {\pi}{6}##

Homework Equations

:[/B]

These equations may help:

20170519_023122.png


The Attempt at a Solution

:[/B]

Please see the pic below:

14951886349821598693691.jpg


It seems correct from my side, but the answer is not matching.
 
Physics news on Phys.org
Is there really a difference :smile: ?
 
BvU said:
Is there really a difference :smile: ?
Couldn't understand... could you explain a bit...
 
Fill in n = 1, 2, 3 in both expressions (yours and the book one) :rolleyes:
 
  • Like
Likes Wrichik Basu
There is a pi radian difference between -pi/6 and 5pi/6, same with pi/6 and -5pi/6. So you can just say it is +-pi/6 + n*pi, where n can be any integer. That covers all of your scenarios.
 
  • Like
Likes Wrichik Basu
scottdave said:
There is a pi radian difference between -pi/6 and 5pi/6, same with pi/6 and -5pi/6. So you can just say it is +-pi/6 + n*pi, where n can be any integer. That covers all of your scenarios.
Why don't you let Wrichik make that discovery himself ?
 
  • Like
Likes Wrichik Basu
scottdave said:
There is a pi radian difference between -pi/6 and 5pi/6, same with pi/6 and -5pi/6. So you can just say it is +-pi/6 + n*pi, where n can be any integer. That covers all of your scenarios.

BvU said:
Why don't you let Wrichik make that discovery himself ?
understood. Thank you.
 
BvU said:
Why don't you let Wrichik make that discovery himself ?
Thanks. I guess I didn't see your response about plugging in 1,2,3, etc when I wrote my suggestion.
 
Back
Top